Altering the flavor of foodstuffs with 3-thia alkane-1,4-diones

ABSTRACT

Methods for altering the organoleptic properties of foodstuffs comprising incorporating with such foodstuffs a small but effective amount of at least one 3-thia alkane-1,4 dione having the formula: WHEREIN R1 and R2 are the same or different and are either hydrogen or lower alkyl, R3 is either hydrogen, lower alkyl, acyl, aroyl, benzyl or phenyl; each of R4 and R6 are the same or different and are either hydrogen or lower alkyl together with compositions containing the 3-thia alkane-1,4 diones for use in altering such organoleptic properties.

United States Patent 1191 Evers et al.

[ Mar. 25, I975 ALTERING THE FLAVOR OF FOODSTUFFS WITH 3-THIAALKANE-l,4-DIONES [75] Inventors: William J. Evers, Atlantic Hightlands;Howard H. Heinsohn, .Ir., Hazlet; Bernard J. Mayers, Cliffwood Beach;Christopher Giacino, Califon, all of NJ.

[73] Assignee: International Flavors & Fragrances Inc., New York, NY.

Filed: June 11, 1974 Appl. No.: 478,279

Related US. Application Data [63] Continuationinpart of Ser. No.386,455, Aug. 7,

1973, abandoned.

Primary E.ramincr.loseph M. Golian Attorney, Agent, or Firm-Arthur L.Liberman Esq.; Harold Haidt, Esq.

[57] ABSTRACT Methods for altering the organoleptic properties offoodstuffs comprising incorporating with such foodstuffs a small buteffective amount of at least one 3- thia alkane-l,4 dione having theformula:

wherein R and R are the same or different and are either hydrogen orlower alkyl, R is either hydrogen, lower alkyl, acyl, aroyl, benzyl orphenyl; each of R and R are the same or different and are either hydrogen or lower alkyl together with compositions containing the 3-thiaalkane-l,4 diones for use in altering such organoleptic properties.

3 Claims, N0 Drawings ALTERING TI-IE FLAVOR F FOODSTUFFS WITH 3-THIAALKANE-l ,4-DIONES This application is a continuation-in-part ofcopending Application for US. Pat. No. 386,455 filed on Aug. 7, 1973 andnow abandoned.

BACKGROUND OF THE INVENTION The present invention provides methods foraltering the organoleptic properties of foodstuffs by adding to suchfoodstuffs quantities of one or more 3-thia alkane- 1,4 diones and itfurther relates to compositions adapted to alter the organolepticproperties of such foodstuffs.

Artificial flavoring agents for foodstuffs have re- (Alk l) I I ceivedincreasing attention in recent years. In many areas, such food flavoringagents are preferred over natural flavoring agents at least in partbecause of the uniform flavor that may be so obtained. For example,natural food flavoring agents such as extracts, essences, concentratesand the like are often subject to wide variation due to changes in thequality, type and treatment of the raw materials. Such variation can bereflected in the end product and results in unreliable flavorcharacteristics and uncertainity as to consumer acceptance and cost.Additionally, the presence of the natural product in the ultimate foodmay be undesirable because of increased tendency to spoil. This isparticularly troublesome in convenience and snack food usage where suchproducts as dips, soups, chips, prepared dinners, canned foods, sauces,gravies and the like are apt to be stored by the consumer for some timeprior to use.

The fundamental problem in preparing artificial flavoring agents is thatof achieving as nearly as possible a true flavor reproduction. Thisgenerally proves to be a difficult task since the magnetism for flavordevelopment in many foods is not understood. This is noteable inproducts having meaty and roasted flavor characteristics. It is alsonoteable in products having vegetablelike and hydrolyzed vegetableprotein-like and aniselike flavor characteristics.

Reproduction of roasted and meat flavors and aromas and vegetable-likeand hydrolyzed vegetable pro-. tein-like and anise-like flavors andaromas has been the subject of the long and continuing search by thoseengaged in the production of foodstuffs. The severe shortage of foods,especially protein foods, in many parts of the world has given rise tothe need for utilizing nonmeat sources of proteins and making suchproteins as palatable and as meat-like as possible. Hence, materialswhich will closely simulate or exactly reproduce the flavor and aroma ofroasted meat product's and liver products and vegetable products arerequired.

Moreover, there are a great many meatcontaining or meat based foodspresently distributed in a preserved form. Examples being condensedsoups, dry-soup mixes, dry meat, freeze-dried or lyophilized meats,packaged gravies and the like. While these products contain meat or meatextracts, the fragrance, taste and vided a-ketothiols and indicated thatsuch a-ketothiols gave rise to savory meat flavors. An example of suchan a-ketothiol is Z-mercapto pentanone-3.

South African Pat. No. 69/4539 dated June 26, 1969 discloses, for use asintermediates for subsequent reaction to form meat flavor compounds1,4-dithioacetyl- 2,3-diketones having the structure:

See page 6 of said South African Patent.

Nothing in the prior art, however, sets forth implicitly or explicitlythe 3-thia-l,4-alkane diones of our invention and their unique andadvantageous and unobvious flavor properties.

THE INVENTION The present invention provides methods for altering theorganoleptic properties of foodstuffs which comprise adding to suchfoodstuffs at least one 3-thia alkane-l,4 dione. Briefly, the methodscomprise adding an amount of at least one 3-thia alkane-l ,4 dionehaving the formula:

3-Mercapto-Zhexanedione having the structure:

3-Thiobenzoyl-2,S-hexanedione having the structure:

XL-Xt 3-Thiopropyl-2,5-hexanedione having the structure:

The novel compounds of our invention may be produced according toprocesses which comprise the steps of:

i. providing a 2-ene-l ,4 dione having the structure:

O C) K2 ii. intimately admixing said 2-ene-1,4 dione with a thiol orthio acid having the formula R SH thereby providing a substituted orunsubstituted Z-thia substitutedl,4dione having the structure:

wherein R, and R are the same or different and are ei- Such materialsmay, if desired, further be hydrolyzed to form 3-mercapto furan havingthe structure:

with an acylating or aroylating agent thus forming a new acyl or aroyl3-thia furan having the structure:

wherein R and R are the same or different and are either-hydrogen orlower alkyl, R is either hydrogen, lower alkyl, acyl, aroyl, benzyl orphenyl, R is the same or different and is either hydrogen or lower alkyland R is aroyl or acyl different from R R or/and R may each be hydrogenin the event that in step (ii) the 2-ene-1,4 dione is admixed with athio acid or thiol having the formula R Sl-l in the presence of anorganic base such as piperidine, pyridine, triethyl amine, quinoline oralpha-picoline or a mixture thereof.

The 2-ene-1,4-dione may be prepared by reacting 2,-5-dialkoxy-2,5-dialkyl-2,S-dihydro furan with a weak acid hydrolysisagent such as 1% aqueous acetic acid under reflux conditions. Theresulting material will be in the case of starting with2,5-dimethoxy-2,S-dihydro furan, cis-3-hexen-2,5-dione.

The resulting 2-enel ,4-dione is then reacted with either a thiol or athio acid having the formula R SH wherein R is lower alkyl, benzyl,phenyl, acyl or aroyl. Examples of such thiols and thio acids are:

thioacetic acid thiopropionic acid thiobutyric acid thioisobutyric acidthio-n-pentenoic acid methyl mercaptan ethyl mercaptan n-propylmercaptan isopropyl mercaptan n-butyl mercaptan isobutyl mercaptann-hexyl mercaptan n-octyl mercaptan n-nonyl mercaptan benzyl mercaptanthiophenol p-tolyl mercaptan m-tolyl mercaptan o-tolyl mercaptanthiocinnamic acid thiobenzoic acid 2-methyl-thiobenzoic acid3-methyl-thiobenzoic acid 4-methyl-thiobenzoic acid2,4-dimethyl-thiobenzoic acid 3,5-dimethyl-thiobenzoic acid Whether anorganic base is used or not in the reaction with the 2-ene-l,4 dionewith the thiol or thio acid having the formula R SH, the 2-ene-l,4 dionecan be exemplified as follows:

Compound R, R R

Name

3-Hexen-2,5-dione Methyl Methyl Hydrogen 3-Methyl-3-hexen-2,5 MethylMethyl Methyl dione 3-Methyl-3-hepten-2,5 Methyl Ethyl Methyl dione3-Ethyl-3-hepten-2,5 Methyl Ethyl Ethyl dione 4-Ethyl-4-octen-3,6 EthylEthyl Ethyl dione 3-Propyl-3-hepten-2,5 Methyl Ethyl Propyl dione4'Methyl-3-hepten-2,5 Ethyl Methyl Methyl dione 4-Methyl-4-octen-3,6Ethyl Ethyl Methyl dione 4-Methyl-4-nonen-3 ,6 Ethyl Propyl Methyl dione4-Propyl-3-hepten-3,6 Ethyl Methyl Propyl dione 5-Methyl-5-decene-4,7Propyl Propyl Methyl dione 5-Methyl-4-nonen-3,6 Propyl Ethyl Methyldione 4-Methyl-3-nonen-2,5 Butyl Methyl Methyl dione 4-Ethyl-3-nonen-2,5Butyl Methyl Ethyl dione 3-Methyl-3-nonen-2,5 Methyl Butyl Methyl dione3-Propyl-3-nonen-2,5 Methyl Butyl Propyl dione 3-Butyl-3-hexen-2,5Methyl Methyl Butyl dione 4-Octen -3 ,6-dione Ethyl Ethyl Hydrogen Asstated above, R, and R can each be hydrogen for the purposes of theseprocesses of our invention in the event that in the reaction of the2-ene-l,4 dione with the thiol or thio acid of the formula R SH, anorganic base is used. Hence, in addition to the foregoing compounds, thefollowing compounds can be utilized in the reaction with R Sl-l:

4-one 4-one Examples of useful organic bases are piperidine, pyridine,quinoline, triethyl amine and a-picoline. in place of such organicbases, radical initiators may be used such as benzoyl peroxide orazobisisobutyl nitrile. The reaction may be carried out in a solventsuch as water or an ether such as diethyl ether or a hydrocarbon such asbenzene or hexane or cyclohexane. The reaction may also be carried outwithout the use of a solvent. The reaction may be carried out underreflux conditions although temperatures varying from 0 up to C aresuitable and will give rise to commercially suitable yields. When thereaction is carried out with highly volatile reactants, e.g., methylmercaptan, higher pressures than atmospheric pressure are preferred,e.g., three atmospheres pressure. Examples of reaction products,3-thia-substituted-l ,4-diones which are formed from the reaction of the2-ene-l,4 diones with the thio acids, and thiols having the formula R SHare as follows:

In addition to being reaction sequence intermediates, f the2-thia-substituted-1,4-diones as exemplified above -lare also useful foraltering the organoleptic properties lof consumable materials, moreparticularly, foodstuffs. iThus, for example,3-thioacetyl-2,5-hexanedione has a roasted meat aroma and a pot-roastand roasted meat flavor tested at levels of 5 ppm. Its flavor thresholdvalue is at 1 ppm. 3-Mercapto-2,S-hexanedione has a roasted meat aromaand a roasted meat flavor at concentrations of 2 ppm with a threshholdvalue at 0.5 ppm. The compound 3.-thiobenzoyl-2,5-hexanedione has aberry and a meat aroma, and an allium, earthy .and horseradish flavor atconcentrations of approximately 0.5 ppm. lts threshhold value is at 0.5ppm. 3-Thiobenzoyl-2,5-hexanedione at 5 ppm evaluated in beef bouillonhas a meaty note. 3-Mercapto-2,5- hexanedione evaluated at 12.5 ppm addsa slight sulphury note (which indeed is desirable) to beef bouillon.3-Thioacetyl-2,5-hexanedione at 5 ppm adds a burnt meat note to beefbouillon. 3-Thiobenzoyl- 2,5- hexanedione adds a slightly green chickenmeat note to chicken broth at 2.5 ppm. 3-Thioacetyl-2,5- hexanedioneadds eggy chicken notes to chicken broth at 2.5 ppm.3-Mercapto-2,S-hexanedione adds chicken sulphury notes to chicken brothat 2.5 ppm.

When used as intermediates, the thio-substituted-l,4- diones of ourinvention are then cyclized to form substituted or unsubstituted3-thiafurans according to the following reaction:

wherein R; and R are the same or different and are each hydrogen orlower alkyl; wherein R is either acyl or aroyl and R is hydrogen orlower alkyl. The resulting 3-thiafurans (novel compounds) may be used assuch for their organoleptic properties or they may be hydrolyzed andthen reacylated or aroylated to form other acyl thia or aroyl thiasubstituted furans (other novel compounds) which have still otherorganoleptic properties useful for flavoring foodstuffs.

Thus, the 3-thia alkane-1,4-dione derivatives and mixtures thereofaccording to the present invention can be used to alter, vary, fortify,modify, enhance, or otherwise improve the organoleptic properties,including flavor and/or aroma, of a wide variety of materials which areingested, consumed, or otherwise organoleptically sensed. The term alterin its various forms will be understood herein to mean the supplying orimparting a flavor character or note to an otherwise bland,

relatively tasteless substance, or augmenting an existing flavorcharacteristic where the natural flavor is deficient in some regard, orsupplementing the existing flavor or aroma impression to modify theorganoleptic character. The materials which are so altered are generallyreferred to herein as consumable materials.

Such 3-thia alkane-l,4 dione derivatives are accordingly useful inflavoring compositions. Flavoring compositions are herein taken to meanthose which contribute a part of the overall flavor impression bysupplementing or fortifying a natural or artificial flavor in amaterial, as well as those which supply substantially all the flavorand/or aroma character to a consumable article.

The term foodstuff as used herein includes both solid and liquidingestible materials for man or animals, which materials usually do, butneed not, have nutritional value. Thus, foodstuffs includes meats,gravies, soups, convenience foods, malt and other alcoholic ornon-alcoholic beverages, milk and dairy products, nut butters such aspeanut butter and other spreads, seafoods including fish, crustaceans,mollusks and the like, candies, breakfast foods, baked goods,vegetables, cereals, soft drinks, snack foods, dog and cat foods, otherveterinary products, and the like.

When the 3-thia alkane-l ,4-dione derivatives according to thisinvention are used in a food flavoring com- 4-Mercapto'2-butanone;

3-Mercapto-4-pentanone;

l-Merc apto- Z-propanone';

Benzaldehyde;

Furfural;

Furfural alcohol;

Z-Mercapto propionic acid;

Z-Pentene;

Alkyl pyrazine;

Methyl pyrazine;

2-Ethyl-3-methyl pyrazine;

Tetramethyl pyrazine;

Polysulfides;

Dipropyl disulfide;

Methyl benzyl disulflde;

Alkyl thiophenes;

2-Butyl thiophene;

2,3-Dimethyl thiophene',

S-Methyl furfural;

Acetyl furan;

2,4-Decadienal;

Guiacol;

Phenyl acetaldehyde;

vS-Decalactone;

d-Limonene;

Acetoin;

Amyl acetate;

Maltol;

Ethyl butyrate;

Levulinic acid;

Piperonal;

Ethyl acetate;

n-Octanal;

n-Pentanal;

l-lexanal;

Diacetyl;

Monosodium glutamate;

Sulfur-containing amino acids;

Cysteine;

Hydrolyzed vegetable protein;

Hydrolyzed fish protein; and

Tetramethyl pyrazine The 3-thia alkane-l ,4-dione derivatives, or thecompositions incorporating them, as mentioned above, can be combinedwith one or more vehicles or carriers for adding them to the particularproduct. Vehicles can be edible for otherwise suitable materials such asethyl alcohol, propylene glycol, water, and the like. Carriers includematerials such as gum arabic, carrageenan, other gums, and the like. The3-thia alkane-l,4-dione compounds according to this invention can beincorporated with the carriers by conventional means such asspray-drying, drum-drying, and the like. Such carriers can also includematerials for coacervating the 3-thia alkane-l,4-dione derivatives (andother flavoring ingredients, as present) to provide encapsulatedproducts. When the carrier is an emulsion, the flavoring composition canalso contain emulsifiers such as monoand diglycerides of fatty acids andthe like. With these carriers or vehicles, the desired physical form ofthe composition can be prepared.

The quantity of 3-thia alkane-1,4-dione derivatives or mixtures thereofutilized should be sufficient to impart the desired flavorcharacteristic to the product, but on the other hand, the use of anexcessive amount of the derivative is not only wasteful anduneconomical, but in some istances too large a quantity may unbalancethe flavor or other organoleptic properties of the product consumed. Thequantity used will vary depending upon the ultimate foodstuff; theamount and type of flavor initially present in the foodstuff; thefurther process or treatment steps to which the foodstuff will besubjected; regional and other preference factors; the type of storage,if any, to which the product will be subjected; and the preconsumptiontreatment, such as baking, frying, and so on, given to the product bythe ultimate consumer. Accordingly, the terminology effective amount andsufficient amount" is understood in the context of the present inventionto be quantitatively adequate to alter the flavor of the foodstuff.

It is accordingly preferred that the ultimate compositions contain fromabout 0.02 parts per million (PPm) to about 250 ppm of 3-thia alkane-l,4-dione derivative or derivatives. More particularly, in foodcompositions it is desirable to use from about 0.05 ppm to 100 ppm forenhancing flavors and in certain preferred embodiments of the invention,from about 0.2 to 50 ppm of the derivatives are included to add positiveflavors to the finished product. All parts, proportions, percentages,and ratios herein are by weight unless otherwise indicated.

The amount of 3-thia alkane-1,4-dione material or materials of ourinvention to be utilized in flavoring compositions can be varied over awide range depending upon the particular quality to be added to thefoodstuff. Thus, amounts of one or more derivatives according to thepresent invention of from about 2 ppm up to 80 or 90 percent of thetotal flavoring composition can be incorporated in such compositions. Itis generally found to be desirable to include from about 10 ppm up toabout 0.1 percent of the 3-thia alkane-l,4-dione derivatives in suchcompositions.

The following examples are given to illustrate embodiments of theinvention as it is preferably preferred to practice it. It will beunderstood that these examples are illustrative and the invention is notto be considered as restricted thereto except as indicated in theappended claims.

EXAMPLE 1 (Preparation of Cis3-hexene-2,5-dione) In a 1000 ml roundbottom flask fitted with con- H denser and magnetic stirrer are placed200 g of 2,5-

concentrated .ysis

dimethoxy-2,5-dimethyl-2,S-dihydrofuran and 200 ml of a 1% aqueousacetic acid solution. The resulting solution is heated to reflux,refluxed for 2 minutes, cooled with an ice bath to 25C and 625 ml ofa 2%sodium bicarbonate solution is added. The solution is saturated byaddition of 23 g of sodium chloride and extracted with methylenechloride (1 X 200 ml and 3 X ml). After drying over sodium sulfateremoval of the methylene chloride in vacuo gives 142 g of crude cis-3-hexene-2,5-dione which by GLC analysis is about 90% product having thestructure:

EXAMPLE ll (Preparation of 3-Thioacetyl-2,S-hexanedione) In a 1000 mlround bottom flask fitted with magnetic stirrer, thermometer, additionfunnel and reflux condenser are placed 142 g of crude cis-3-hexene-2,5'-dione (ex Example I), 380 ml of ether and 5 drops of piperidine. Thioacetic acid (96.6g) is added over a period of 1 hour. When aboutone-eighth of the thio acetic acid is added the solution begins toreflux which continues during the remainder of the addition. Afteraddition is complete the mixture is'allowed to stand for 85 minutes.Ether is then removed in vacuo (water asperator) to give 235 g of crudematerial containing about 91% 3-thioacetyl-2.5-hexanedione. Distillationof a 134 g portion of the crude gives 84.5 g of3-thioacetyl-2,5-hexanedione boiling at 86 to 87C at 0.5 torr. NMR, IRand mass spectral analysis confirm the structure:

EXAMPLE ll] (Preparation of 3-Mercapto-2,5-hexanedione) To 150 ml of a2% sodium hydroxide solution in a flask fitted for stirring is added 10g of 3-thioacetyl-2,5-

hexanedione. After stirring for 1 hour the pH of the mixture is adjustedto 5-6 by the addition of dilute (10%) hydrochloric acid, the solutionis saturated with sodium chloride solution and extracted with ether (4 X25 ml). The ether extracts are combined, washed with saturated sodiumchloride solution (15 ml), dried and in vacuo to give 6.2g of crude3-mercapto-2,5-hexanedione. Vacuum distillation gives 2.5 g of3-mercapto-2,5-hexanedione boiling at 57-59C at 0.85 torr. NMR, IR andmass spectral analconfirm the structure as 3-mercapto-2,5- hexanedione.

EXAMPLE lV (Preparation of 2-Thioacetyll ,4-butane-dial) A. Preparationof 2-Butone-l,4-dial A mixture of 2,5-dimethoxy-2,5-dihydrofuran (20 g),water (80 ml) and acetic acid (3 drops) is stirred for minutes at roomtemperature, 22 minutes at 40C and 90 minutes between 60C and 75C. GLCanalysis at this point indicates 15.7% starting material and 83.5%2-butene-l,4-dial. The mixture is cooled to 25C and sodium bicarbonate(0.3 g) is added. B. Preparation of 3-Thioacetyl-1,4-butanedial To theaqueous solution obtained in A, supra, is added 10 g of thiolacetic acidduring a 14 minute period. During the addition, the temperature is keptbelow 30C by intermittent application of a cooling bath. After 110minutes, the reaction mixture is extracted with methylene chloride (3 X35 ml). The combined methylene chloride extracts are dried and thenconcentrated in vacuo to give 17.3 g of yellow oil containing about 80%2-thioacetyl-1,4-butanedial. The compound is identified through massspectral, NMR and IR analysis as having the structure:

{remaining fieaks in I M.S. No molecular, ion; remaining peaks indecreasing intensity 43, 29, 27, 45, 55, 60, 84, 100 and 142 m/e units.

NMR (CDCl;,) 8 2.38 (s,3) 3.02 (multiplet 2J=10H) 4.46 t,1,J=10Hz), 9.40(s,1 and 9.68 (s,l) ppm. IR (thin film) 2850, 2750, 1720, I700(shoulder),

1388, 1352, 1132 and 958 cm EXAMPLE V (Preparation of3-Thioacetyl-4-oxo-pentanal A. 4-Oxo-2-pentanal Into a 5 liter,three-necked flask fitted with mechanical stirrer, thermometer andvacuum take-off are placed 600 g of 2-methyl-2,5-dimethoxy-2,5-dihydrofuran and 2400 ml of deionized water. After 20 minutes ofstirring at room temperature, the mixture becomes homogeneous and has apale yellow green color. Analysis of a sample of the reaction mixture byGLC after 3.25 hours shows 22% methanol, 67% 4-oxo-2-pentanal and 9%starting material. Vacuum (26 torr.) is applied to the reaction mixturewhile maintaining the temperature of the reaction mixture between 25 and30C. After 3.25 hours GLC analysis shows 13% methanol, 82%4-oxo-2-pentanal and 3.2% starting material. The vacuum is removed andthe reaction mixture is allowed to stand at room temperature overnight.Analysis after standing overnight shows 12.9% methanol, 85%4-oxo-2-pentanal and 2.1% starting material. B.3-Thioacetyl-4-oxo-pentanal In a 5 liter, three-necked flask fitted withmechanical stirrer, thermometer and addition funnel are placed 2325 mlof the solution obtained in (A) and 2 ml of piperidine diluted in 5 mlof water. To this solution is added a mixture of thiolacetic acid (292.3g) and piperidine (13 ml) over a 20 minute period. After standing anadditional minutes, ml of concentrated hydrochloric acid is added, theresulting mixture poured into a separatory funnel and the oil layerremoved. The aqueous layer is extracted with benzene (500 ml) andmethylene chloride (2 X 500 ml). The benzene extract is co mbinend withthe oil layer and the mixture is dried over sodium sulfate. Themethylene chloride extracts are combined and dried over sodium sulfate.Solvent removal in vacuo (40-45 bath at 15 torr.) gives 414.5 g of crudeoil from the benzene extract and 172.5 g of crude oil from the methylenechloride extracts. The crude oil is distilled under vacuum to give amixture of, 3-thioacetyl-4-oxo-pentanal and 2-thioacetyl-4-oxopentanalboiling at 94-98C at 0.3-0.55 mm Hg.

EXAMPLE Vl (PREPARATION OF S-THIOBENZOY L-2,5-HEXANEDIONE) In a 50 mlthree-necked flask equipped with thermometer, 10 ml addition funnel andmagnetic stirrer is placed 6 gm of 2,5-dimethoxy-2,5-dimethyl-2,5-dihydrofuran, 24 ml H 0 and 1 drop of glacial acetic acid. The mixtureis stirred for one hour until homogeneous. Then 5.25 gm thiobenzoic acidis added over a five-minute period. The mixture is allowed to stand foreighteen more minutes and is then extracted with 35 ml of methylenedichloride. After drying over anhydrous sodium sulfate and subsequentsolvent removal, 7.55 gm of crude 3-thiobenzoyl-2,S-hexanedione isrecovered. The crude material is purified by column chromatography on108 gm silicic acid packed in etherzhexane (1:9) mixture. Elution with630 ml etherzhexane (1:9) solvent mixture; followed by elution with 500ml ether:- hexane (1:4) solvent mixture; followed by elution with 850 mletherzhexane (1:3) solvent mixture gives 6.2 gm of3-thiobenzoyl-2,5-hexanedione, having the following analysis:

MS: Parent Ion, then decreasing order: 250, 105, 77, 43, 128, 106 NMR(CDCl;,): 7.96 (d,1,J=2I-lz), 7.88 (d,1,J=2Hz), 7.48 (m,3), 4.78(q,1,J=5I-Iz), 3.06 (m,2), 2.20 PP IR (KBr plate, thin film): 3060,3000, 2960, 2910, 1709, 1661, 1590, 1578,1445, 1355, 1204, 1172, 1154,900, 759, 681, 640 cm EXAMPLE VII The following formulation is prepared:

Ingredient Parts by Weight Liquid h drolyzed vegetable protein 90.004-Methy -5-beta-hydroxy-ethyl thiazole 5.00 Tetrahydro thiophene-3-one1.00 Furfuryl mercaptan 0.01 2-Nonenyl 0.50 Difurfuryl disulfide 0.49Dimethyl sulfide 0.50 Methyl mercaptan 0.50 3-Thioacetyl-2,S-hexanedione2.00

EXAMPLE VIII PREPARATION OF 3-THIOISOVALERYL-2,5-HEXANEDIONE In a 250 mlthree-necked flask fitted with magnetic Distillation of the crude gives10.8 g product boiling at 1081l0C at 0.8 0.9 mm Hg pressure and having hl ol it a nalyxsi Mass Spectral Analysis In decreasing order (no parention): 43, 57, 85, 128 NMR Spectrum (CDCl:,)

4.60 (q,l) 2.95 111,5 2.32 5,3 2.17 (8,3) 0.99 (d,6) PPm EXAMPLE IXPreparation of 2-Propyl-3-Thioacetyl Furan' A. Preparation Of2-Propyl-2,5-Dimethoxy-2,5- Dihydro Furan From 2-Propyl Furan ReactionCH CH Into a 500 ml three-necked reaction flask equipped with mechanicalstirrer, calcium carbonate drying tube and thermometer, the followingmaterials are placed:

(i) Z-Propyl furan 25.0 g

(0.227 moles) (ii) Methanol, absolute 180 ml (iii) Sodium carbonate 47.1g

(0.454 moles) The reaction mass is cooled to l0C using a dry-ice acetonebath. Over a period of minutes, a solution of 36.3 grams of bromine in70 ml absolute methanol. is added dropwise while maintaining thereaction mass at l2C to 13C. After the addition of the bromine solution,the reaction mass is stirred for 1.5 hours while maintaining same at 10C.

The reaction mass is then mixed with 450 ml of saturated sodium chloridesolution. The resulting mixture is suction filtered and the filter cakeis washed with ml of methylene dichloride. The resultant filtrate andwashings are placed in a separatory funnel and the lower organic phaseis drawn off. The aqueous phase is extracted with two 100 ml portions ofmethylene dichloride and the organic solutions are combined. The organicsolution is then dried over anhydrous sodium sulfate and filtered; andthen concentrated in vacuo to a yellow liquid weighing 32.7 grams. Themajor peak of this material determined by GLC contains 2-propyl-2,5-dimethoxy-2,5-dihydro furan (GLC conditions: F and M 5750; 8 feet XA inch; SE-30; 225C per min., flow rate 80 ml/minute, chart speed 0.25inch per minute).

B. Preparation Of 4-Oxo-2-l-leptenal Reaction Into a 250 ml threeneckedreaction flask equipped with mechanical stirrer and thermometer thefollowing materials are added:

(i) 2-Pro yl-2,5-dimethoxy 32.7 g

2,5di ydrofuran prepared (0.16 moles) according to the process of Part A(ii) Water (distilled) 325 ml The reaction mass is stirred for a periodof 4 hours at 24C. At the end of this period of time, the reaction massexists in two phases: an aqueous upper phase, and an organic lowerphase. The aqueous upper phase is decanted and placed in a one litervessel for the following reaction C.

C. Reaction Of 4-Oxo-Heptenal With Thioacetic Acid Reaction To thestirred aqueous solution produced in Part B, supra, of 4-oxo-2-heptenalis added 0.4 ml piperidine. After the piperidine addition, 12.4 grams ofthioacetic acid is added to the reaction mass over a period of 4 minuteswhile maintaining the reaction mass at a temperature in the range of2732C. After the thioacetic acid addition is complete, the reaction massis stirred 15 16 for 1.5 hours. The reaction mass is then placed in a W(CD613) separatory funnel and extracted with 100 ml of methyly enedichloride. The methylene dichloride solution is r mac-126512192 thenseparated, dried over anhydrous sodium sulfate and concentrated to anorange oil weighing 23.8 grams. g 1 01 3) m gi-[ This orange oil isanalyzed using GLC and determined to contain two isomers having theabove structures.

Mass Spectral Analysis of Trap l:

Molecular Ion, then in decreasing intensity: 202, 43, 1 .65 (m, 2) CH C1:l CH

2s, 71, 55, 41, 97, 83 m/e Mass Spectral Analysis of Trap ll:

Molecular lon, then in decreasin intensit 202, 28, O

43,71,99 m/e g y .3 ,3) l D. Preparation Of 2-Propyl-3-Thioacetyl Furanl5 3 Reaction What is claimed is:

l. A process for altering the flavor of a foodstuff which comprisesadding to said foodstuff from about 0.02 to about 250 parts per millionof at least one compound having the structure:

Into a 500 ml flask, equipped with reflux condenser,

calcium chloride drying tube, mechanical stirrer, thermometer andaddition funnel, the following materials are placed.

(i) lsopropenyl acetate 175 ml 1) Concentrated u fu c d m1 wherein R,and R are the same or different and are either hydrogen or lower alkyl,R is either hydrogen, a lower alkyl, acyl, aroyl, benzyl or phenyl; eachor R The mass heated to reflux (93 C) over a Penod 5 and R are the sameor different and are either hydroof 20 minutes, while maintaining thereaction mass gen or lower alkyl. temperatfue at a l of grams of 2. Theprocess for altering the flavor of a foodstuff the reaqllon Product ofPart 1 25 ml of Sopropenyl which comprises adding to said foodstuff fromabout acetate 18 added from the addition funnel to the reac- 0.02 toabout 5 parts per mime" f a compound tion mass with stirring Thereaction mass is then stirred lected from the group consisting of; andmaintained at 91 C for a period of 30 minutes at 3 Thi0acety| 25hexanedione; which point 5.0 grams of sodium bicarbonate is added 3Mercapto z,5 hexanedione; to the t 3-Thiobenzoyl-2,5-hexanedione; and

The isopropenyl acetate cychzation agent 18 then drs- 3 Thioprpy| 2,5hexanedione tilled Off at a P? temperature of and he'ad f 3. The processfor altering the flavor of a foodstuff p i 50 C Hg pressure- Theresulting Teslwhich comprises adding to said foodstuff from about dueadn 11Xed Wlth ml bellzene and 50 ml Water- 0.02 to about 250 parts permillion of at least one com- The resulting mixture lS placed into aseparatory funnel pound having the Structure; and the layers areseparated. The benzene layer is filtered through anhydrous sodiumsulfate and is then p concentrated in vacuo to a brown liquid weighing5.0 V R grams. This liquid is distilled through a short pathmicrodistillation apparatus at 100-l03C and 0.3 mm Hg pressure, yielding2-propy1-3-thioacetyl furan as confirmed by mass spectral and NMRanalysis. Mass Spectral Analysis:

Molecular lon, then in decreasing intensity: 184, 1 13,

wherein R and R are thesame or different and are either hydrogen oflower alkyl, R is either hydrogen, lower alkyl, acyl, aroyl, benzyl orphenyl; each of R and R are the same or different and are eitherhydrogen or lower alkyl and, in addition, at least one adjuvant materialselected from the group consisting of:

Methyl thiazole alcohol;

Z-Methyl butanethiol;

4-Mercapto-2-butanone;

3-Mercapto-4-pentanone;

l-Merc apto-2-propan0ne;

Benzaldehyde;

Furfural;

Furfural alcohol;

2-Mercapto propionic acid;

Z-Pentene;

Alkyl pyrazine;

Methyl pyrazine;

2-Ethyl-3-methyl pyrazine;

Tetramethyl pyrazine;

Dipropyl disulfide;

Methyl benzyl disulfide;

Alkyl thiaphenes;

2-Butyl thiaphene;

2,3-Dimethyl thiaphene;

Sulfur-containing amino acids;

Cysteine;

Hydrolyzed vegetable protein;

l-lydrolyzed fish protein; and Tetramethylpyrazine.

1. A PROCESS FOR ALTERING THE FLAVOR OF A FOODSTUFF WHICH COMPRISESADDING TO SAID FOODSTUFF FROM ABOUT 0.02 TO ABOUT 250 PARTS PER MILLIONOF AT LEAST ONE COMPOUND HAVING THE STRUCTURE:
 2. The process foraltering the flavor of a foodstuff which comprises adding to saidfoodstuff from about 0.02 to about 250 parts per million of a compoundselected from the group consisting of: 3-Thioacetyl-2,5-hexanedione;3-Mercapto-2,5-hexanedione; 3-Thiobenzoyl-2,5-hexanedione; and3-Thiopropyl-2,5-hexanedione.
 3. The process for altering the flavor ofa foodstuff which comprises adding to said foodstuff from about 0.02 toabout 250 parts per million of at least one compound having thestructure: